Good age to Starr leaving baby home with nanny/sister/babysitter?

I am a MD. I am the head of neonatal surgery, Obsteticans, and gynaecology, and an F.A.C.S. I recently had twin girls, Madelyn and lizzi. My oldest daughters, Kristen and samantha babysit them, and thier other younger sisters, but I don't know when would be a good time to return to the hospital. I work wierd hours(extremely wierd). The hospital has a daycare in it, but I don't like tge lady running it. I enjoy surgery, but the unpredictable hours and such dedication make it hard. I'm not allowed to opperate until it's been 4 weeks since I have recovered from the birth, so it will be about four weeks until I CAN. Once I start working again, I can take maternaty leave. Thanks.